Language:
كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
(77)
Chapter: Hajjat-ul-Wada
(77)
باب حَجَّةُ الْوَدَاعِ
Sahih al-Bukhari 4411

Narrated Ibn `Umar:

During Hajjat-ul-Wada`, the Prophet (ﷺ) and some of his companions got their heads shaved while some of his companions got their head-hair cut short.

حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، حَدَّثَنَا مُحَمَّدُ بْنُ بَكْرٍ، حَدَّثَنَا ابْنُ جُرَيْجٍ، أَخْبَرَنِي مُوسَى بْنُ عُقْبَةَ، عَنْ نَافِعٍ، أَخْبَرَهُ ابْنُ عُمَرَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم حَلَقَ فِي حَجَّةِ الْوَدَاعِ وَأُنَاسٌ مِنْ أَصْحَابِهِ وَقَصَّرَ بَعْضُهُمْ‏.‏
Reference : Sahih al-Bukhari 4411
In-book reference : Book 64, Hadith 433
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 695
  (deprecated numbering scheme)